A Vlasov equilibrium previously developed <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> for steady state emission into a magnetized gap in coaxial geometry is equipped with electron, ion and neutral surface emission rules that accurately support the solution profiles. These algorithms are formulated in terms of novel drift kinetic fluid particle (DKFP) methods that conserve number, momentum, and enthalpy to machine precision. The cathode boundary conditions are those of a perfect conductor that emits a electron flux radially, azimuthally, and axially. The anode boundary conditions are those of a perfectly absorbing conductor. The cathode carries a fixed current and the radial gap is set to a fixed voltage. The angular momentum of emitted electrons around the cathode is found to materially change the orbit turning points. When energy conserving solutions are examined it is found that axial velocities must remain bounded above by a well defined function of radius, magnetic field, and voltage. A fully nonlinear and self consistent Vlasov-Poisson problem is formulated and solved for the space charge distribution implied by the Vlasov equilibrium. Moments of the Vlasov distribution then determine the shunt impedance of the gap and the criteria for "warm" magnetic insulation of the coaxial line. The DKFP emission scheme must then benchmark to these profiles in the gap if it is to resolve these steady state properties. The theory limits to Ottinger's critical current magnetization picture for cold electrons, but shows a properly non-singular behavior in the electron density profile at the radial turning points and so properly reduces the enhancement of ion flux across the gap.

Since monolaurin, a monoglyceride formed in the human body in small quantities, has proven effective both in vitro and in vivo against certain strains of Staphylococcus aureus, an important question arises whether consuming a substance high in lauric acid content, such as coconut oil could increase intrinsic monolaurin production to levels that would be successful in overcoming staphylococcal and other microbial invaders. Both a cup plate method and a microdilution broth culture system were employed to test bacteriostatic and bactericidal effects of the test agents in vitro. To test effectiveness in vivo, female C3H/he mice (10-12 per group) were orally administered sterile saline (regular control), vancomycin (positive control), aqueous monolaurin, or two varieties of coconut oil (refined, bleached, deodorized coconut oil and virgin coconut oil) for 1 week before bacterial challenge and 30 days after. A final group received both monolaurin and vancomycin. In contrast to monolaurin, the coconut oils did not show bactericidal activity in vitro. In vivo, the groups receiving vancomycin, monolaurin, or the combination showed some protection--50-70% survival, whereas the protection from the coconut oils were virtually the same as control--0-16% survival. Although we did not find that the two coconut oils are helpful to overcome S. aureus infections, we corroborated earlier studies showing the ability of monolaurin to do such.

The purpose of this study was to determine whether overlap between temporary external fixator pins and definitive plate fixation correlates with infection in high-energy tibial plateau fractures. Retrospective chart and radiographic review. Academic medical center. Seventy-nine patients with unilateral high-energy tibial plateau fractures formed the basis of this report. Placement of knee-spanning external fixation followed by delayed internal fixation for high-energy tibial plateau fractures treated at our institution between 2000 and 2008. Demographic patient information was reviewed. Radiographs were reviewed to assess for the presence of overlap between the temporary external fixator pins and the definitive plate fixation. Fisher exact and t test analyses were performed to compare those patients who had overlap and those who did not and were used to determine whether this was a factor in the development of a postoperative infection. Development of infection in those whose external fixation pin sites overlapped with the definitive internal fixation device compared with those whose pin sites did not overlap with definitive plate and screws. Six knees in six patients developed deep infections requiring serial irrigation and débridement and intravenous antibiotics. Of these six infections, three were in patients with closed fractures and three in patients with open fractures. Two of these six infections followed definitive plate fixation that overlapped the external fixator pin sites with an average of 4.2 cm of overlap. In the four patients who developed an infection and had no overlap, the average distance between the tip of the plate to the first external fixator pin was 6.3 cm. There was no correlation seen between infection and distance from pin to plate, pin-plate overlap distance, time in the external fixator, open fracture, classification of fracture, sex of the patient, age of the patient, or healing status of the fracture. Fears of definitive fracture fixation site contamination from external fixator pins do not appear to be clinically grounded. When needed, we recommend the use of a temporary external fixation construct with pin placement that provides for the best reduction and stability of the fracture, regardless of plans for future surgery.

AbstractUsing survey evidence collected from social security organizations and contribution collection agencies, a major aim of this article is to advance knowledge sharing and good practice on contribution collection and the enforcement of compliance. Although contribution collection and compliance have important social protection, political and fiscal dimensions, this article frames the pursuit of these objectives as an aspect of administrative good governance. The evidence suggests that seven core factors combine often to form the basis of success in contribution collection and compliance. In addition to improving benefit adequacy and the financial health and public standing of programmes, such success may support also national and international efforts to extend social protection coverage. Ultimately, the achievement and scale of any such success may be determined and delimited by the broader national policy environment, over which most social security organizations have little or no influence.

ResumenA tenor de las pruebas recopiladas en las encuestas realizadas a las organizaciones de la seguridad social y los organismos de recaudación de cotizaciones, uno de los objetivos principales de este artículo es compartir los conocimientos y las buenas prácticas adquiridas en la recaudación de cotizaciones y el cumplimiento del sistema. Aunque la recaudación de cotizaciones y el grado de cumplimiento del sistema tienen importantes dimensiones de protección social, política y fiscal, este artículo formula estos objetivos como aspectos de una buena gobernanza administrativa. Las pruebas recopiladas sugieren que hay siete factores fundamentales que suelen combinarse para que la recaudación de cotizaciones y el cumplimiento del sistema sean un éxito. Además de mejorar la adecuación de las prestaciones, la salud financiera y el prestigio público de los programas, este buen funcionamiento puede propiciar también una serie de iniciativas nacionales e internacionales para ampliar la cobertura de la protección social. En última instancia, el cumplimiento satisfactorio y el alcance de estos programas pueden venir determinados y condicionados por las condiciones generales de la política nacional, sobre las cuales la mayoría de las organizaciones de seguridad social ejercen una escasa o nula influencia.

Standard techniques for immobilization of a tibia shaft fracture in the emergency department in a long-leg splint can be cumbersome, technically difficult, and often requires the use of an assistant. We have developed a novel technique for the reduction and splinting of tibial shaft fractures, which uses a "hammock" constructed of stockinette, which allows a single consulting orthopaedic physician to rapidly reduce and place a long-leg plaster splint or cast on a patient. This technique was performed on 12 consecutive patients with a total of 12 tibial shaft fractures. Translation, angulation, and shortening of the fracture were documented in anteroposterior and lateral views of the injured tibia and these parameters were compared against values measured after the hammock technique was used to reduce and splint the fracture. Pre-"hammock" average values for fracture displacement in the anteroposterior plane for translation, angulation, and shortening were 10.5 mm (53.1%), 12.0°, and 9.4 mm, respectively. Post-"hammock" average values for fracture displacement in the anteroposterior plane for the same parameters were 8.7 mm (44.4%), 4.2°, and 7.9 mm, respectively. Pre-"hammock" average values for fracture displacement in the lateral plane for translation and angulation were 4.9 mm and 8.7°. Post-"hammock" average values for fracture displacement in the lateral plane for the same parameters were 4.9 mm and 2.0°, respectively. These results show that this technique is able to achieve the goals of fracture reduction and immobilization in a rapid fashion when help is not available.

AbstractMinerals that are essential to life are the source of metals and other inorganic elements involved in the most fundamental processes. For example, oxygen is utilized in the human body with the help of metal complexes. The human skeleton is composed of calcium and phosphorus and traces of other metals. The regulation of body‐fluid volume and acid‐base balance requires sodium, potassium, magnesium, and calcium. Several vitamins contain sulfur, one contains cobalt. Hormones contain iodine, sulfur, and zinc. States of dynamic equilibrium exist for the various mineral nutrients as well as mechanisms whereby a system can adjust to varying amounts of these minerals in diet. In forms usually found in foods, most mineral nutrients are not toxic when ingested orally. RDAs (recommended dietary allowances) can generally be eaten without concern for safety. The essential minerals are classified as either principal elements or trace and ultratrace elements. Principal elements are calcium, phosphorus, sulfur, sodium, potassium, chlorine, and magnesium, Trace and ultratrace elements are iron,fluorine, zinc, copper, boron, selenium, iodine, manganese, molybdenum, chromium, cobalt, tin, vanadium, nickel, and arsenic. All are discussed in this article.

Bone morphogenetic proteins (BMPs) play important roles in the stimulation of osteogenesis and osteoinduction during bone fracture healing and their expression levels may be important for bone graft efficacy. The objective of this study was to determine if there are variations in the expression of BMPs and their receptors in various bone graft harvesting sites. We analyzed autogenous marrow aspirates obtained from three different graft sites for the mRNA levels of BMPs and their receptors. Using real-time polymerase chain reaction, we analyzed the mRNA levels of BMPs and their receptors in autogenous bone marrow aspirates obtained from three different bone graft sites of 10 different human subjects. Collection of autogenous bone marrow from the iliac crest, the proximal humerus, and the proximal tibia was performed using standard sterile techniques in the operating room as part of surgery to treat an established fracture nonunion. The mRNA levels of BMP-2 and BMP-5 were the highest in the bone marrow aspirates from the three different sites, whereas the mRNA levels of the other osteoinductive BMPs (BMP-4, -5, -6, -7, -8, and -9) were lower. The mRNA levels of BMP-3, an inhibitor of osteogenesis, were the lowest in the bone marrow aspirates of all three different sites. There were no statistical significant differences in the mRNA levels of any of the BMPs or their receptors investigated in this study in the bone marrow of the three different sites. Because no statistical significant differences in the mRNA levels of the BMPs and their receptors were detected in the bone marrow aspirates from the three different sites, our findings suggest that potential differences of various graft sites in the augmentation of bone healing does not result from different expression levels of BMPs.

Locked plate technology has evolved in an effort to overcome the limitations associated with conventional plating methods, primarily for improving fixation in osteopenic bone. The development of screw torque and plate-bone interface friction is unnecessary with locked plate designs, significantly decreasing the amount of soft tissue dissection required for implantation, preserving the periosteal blood supply, and facilitating the use of minimally invasive percutaneous bridging fixation techniques. The locked plate is a fixed-angle device because angular motion does not occur at the plate screw interface. The use of locked plate technology allows the orthopaedic surgeon to manage fractures with indirect reduction techniques while providing stable fracture fixation. The secure 'feel' of locked plates, ease of application, and the low incidence of complications noted in early clinical reports have contributed to the proliferation of this technology. Along with reports of clinical successes, as the use of fixed angle/locked plates has increased, clinical failures are being noticed. This review will focus on the biomechanics of locked plate technology, appropriate indications for its use, laboratory and clinical comparisons to conventional plating techniques, and potential mechanisms of locked plate failure that have been observed.